Handheld folding knives have been used for many years for self-defense. Using a folding knife as a weapon first requires withdrawing the knife from a contained location, such as from a pocket, a sheath, a holster, or a container. The second aspect of using a folding knife as a weapon is to unfold the knife. Using a folding knife can be significantly difficult in a stressful situation, such as self-defense. Stress increases the difficulty of performing ordinary motor skills. Advanced motor skills often require extensive and dedicated training. When an individual is confronted with a situation that demands stress management and the execution of advanced motor skills, a successful outcome may be very challenging.
As mentioned, achieving a successful draw and unfolding of a folding knife while under stress requires training. Envision drawing a weapon while managing a physical attack. The isolated routine of a draw is now combined with a multitude of movements which severely complicate the process. Now envision the requisite skill and composure to unfold the knife. In practice, the draw and unfolding of a folding knife is measured not in seconds, but in fractions of a second. Therefore, a means for enabling the simultaneous drawing and unfolding of a folding knife will increase survivability.
The basic concept behind a folding knife is that it can be stored in a pocket or container. A folding knife occupies a small amount of space in one's pocket and is also safe to handle when in the folded position as the blade is securely stored in the handle.
Historically, folding knives have been opened with two hands (e.g., the “Swiss Army” knife) but this operation has evolved to single-handed operation. There are a number of ways to open folding knives with one hand. The most common single-hand operation is to use the thumb to engage some geometry that is designed to increase the thumb's leverage on the blade. See for example U.S. Pat. No. 4,095,337 to Pharr. These geometries come in many shapes and sizes. Some geometries are formed out of the blade itself while others are attachments which are fastened to the blade in various ways. Another single-handed operation is the wrist-flick method. This method is facilitated by reducing the blade's pivoting resistance so that a quick flick of the wrist swings the blade into an unfolded and locked position. Yet another single-handed operation of folding knives is the classic switch-blade. By depressing a release button on the knife, a retaining latch is opened, allowing a spring-loaded blade to unfold to a locked position. These methods do not meet the special needs described above.
Thus, there is a need for providing apparatus and procedures for modifying a conventional folding knife so that the knife may be drawn and unfolded automatically and speedily. It would be advantageous to be able to open a folding knife with the use of only one hand to draw the knife. It would be advantageous that the procedure not require any additional hand or finger manipulation of the folding knife to unfold it during removal from a container, other than gripping the knife and simply withdrawing it from a holster, pocket or other container.